1. Field of the Invention
The present invention relates to a semiconductor light emitting element such as a light emitting diode (LED) or a semiconductor laser diode (LD), and more particularly relates to semiconductor light emitting elements having a capacitor, and a method for manufacturing the same.
2. Description of the Related Art
The semiconductor light emitting elements, such as LEDs and LDs, are manufactured having various wavelengths, luminance and light intensities dependent on the selection of semiconductor materials and structures of the elements.
FIGS. 12(a) and (b) show the structure of a conventional gallium nitride-based compound semiconductor (In.sub.x Ga.sub.y Al.sub.(1-x-y) N: 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1) LED (Japanese Patent Laid-Open Publication No. H6-338632). This LED has a structure in which an n-type compound semiconductor layer 112 and a p-type compound semiconductor layer 114 are sequentially deposited on a sapphire substrate 101. The p-type semiconductor layer 114 is partly etched to expose the n-type semiconductor layer 112. A cathode 105 is formed on the n-type semiconductor layer 112 and a translucent anode 107 made of a thin film metal is formed on the p-type semiconductor layer 114. After the wire bonding step, balls 161, 162 are formed on a base electrode 118 which is formed on the anode 107 and on the cathode 105. The current flows between the bonding wires 79, 78. The light is emitted by the recombination of the electrons and the holes on the pn-junction.
It was clarified by our experiments on the reliability of LEDs that deterioration of characteristics such as lowering of a luminous efficiency takes place when a high voltage is applied. For example, deterioration occurs when LEDs are touched by a person, soldered, plugged in or out, switched on or off, or impressed instantaneously with a high voltage (surge) generated by a drive circuit etc. Therefore, LED handling must be done with extreme care. Such disadvantages are noticeable with LEDs which have both the anode and the cathode on the same plane. Such disadvantages are noticeable with LEDs which have a transparent electrode formed of a thin film metal.